Cheap Microwave

There is not that much bouncing as the weight of the camper minimizes travel unless you hit a large hole or bride expansion joint area. The microwaves for RV use are standard microwaves that are mounted with a front grill so they will not bounce but are going to fail quicker as they are cheaper units inside but with a high price tag.

I go by the customer reviews on Amazon or at Home Depot. Easy enough to fill the gap between the microwave and the top of the cabinet while traveling to keep it from moving and we do that anyway as space in the kitche is at a premium.